The Neuropathology Core of the ADCC functions to provide neuropathologic diagnoses for patients studied by the Clinical Core and to provide brain tissue, CSF, blood serum and DNA for studies by basic scientists. The Neuropathology Core in this application is based at Sun Health Research Institute, where a brain donation program devoted to Alzheimer's disease (AD) research has already been in existence for more than 10 years. Over this time period, more than 600 brains (approximately 50% AD, 25% non-demented controls) have been collected, stored and disbursed to more than 200 AD researchers located all over the world, as well as 4 separate AD laboratories within the Institute, 3 of which have receive NIH funding. Particular strengths of the brain donation program at the Institute include a short postmortem delay (averaging less than 3 hours) and a large number of non-demented control donors. Aside from AD, the full spectrum of dementing disorders is represented, with substantial numbers of cases from even the rarer of these conditions. More than 600 living individuals have consented to brain donation and are being followed with periodic neuropsychological assessments as well as screening tests for extrapyramidal movement disorders. Autopsy cases are fully characterized neuropathologically and are all genotyped for apolipoprotein E alleles. Over the 5 years of the proposed ADCC granting period, approximately 300 cases will come to autopsy; all clinical sites will contribute to this caseload.